Talk:Bijective proof

Technical template
Except no one has bothered to say why this is too technical.

should every page that uses the word "bijective" include its definition? would more pictures help? —Preceding unsigned comment added by Bcent1234 (talk • contribs)


 * Let's see... according to the page history, it was User:Woohookitty, back on 2006-01-06, who added to the article, writing in the edit summary: "really needs to be dumbed down. alot."   I will go ask that user to drop by here to discuss the problem in more detail. -- Stebulus 20:38, 13 July 2006 (UTC)


 * Please itemize explicitly what needs further explanation or additional links to prerequisite knowledge to understand this article. This article provides plenty of links to prerequisite knowledge and explains the concept succinctly as presented in undergraduate mathematics courses on graph theory and combinatorics.  Just because some reader says "ooooOOOOoooo, this whole topic makes my head hurt!  I am bored." does not justify a { { technical } } demerit.  If a well-justified list of requested improvements that do not damage the technical content fails to appear below, I propose removing the { { technical } } demerit in coming weeks/months. —optikos 02:40, 19 September 2006 (UTC)

I agree that the article does not seem to be overly technical. I think it would be nice to add the details of one of the harder proofs, such as Catalan numbers, or the Young Tableaux for the integer partitions. Ptrillian 11:50, 3 January 2007 (UTC)

This is one case in which I agree that someone could be done fairly easily to make this more comprehensible to a lay audience. Maybe I'll be back.... Michael Hardy (talk) 18:10, 21 August 2008 (UTC)

...OK, I've added two concrete examples that should be comprehensible to secondary-school pupils and others who are not professional mathematicians. What was here before that should have been comprehensible to secondary-school pupils who follow the course usually offered to more mathematically inclined pupils, but maybe not to others. Michael Hardy (talk) 18:34, 28 August 2008 (UTC)

Concrete Examples
I removed them since they are too specialized and add little to the article. These would be appropriate for WP pages dealing with binomial coeff. bijections. As it stands, they carry undue weight for being "examples within examples" of general bijections. I would however encourage more general examples to be added to this page. Mhym (talk) 20:44, 28 February 2012 (UTC)
 * This page indeed lacks good examples. And I would suggest to remove Pascal's triangle reccurrence formula example as well. Where is the bijection? At the very best I can see a double counting in this example, but not a bijection. --MathsPoetry (talk) 12:53, 21 December 2012 (UTC)
 * It is now six years later and this "example" is still here. More emphatically, this is not a bijective proof and does not illustrate anything about bijective proofs. As with most proofs at this level, with a great deal of work this could be hammered into a bijective proof, but then it would lose all pretense of being a basic example and likely to be OR as well. I'll give it a week for someone to find a true bijective proof, and if no one can I'll remove the example. --Bill Cherowitzo (talk) 20:05, 28 December 2018 (UTC)

Added a clarifying illustration
I have added a simple illustration to clarify the exposition of the proof of the "symmetry of the binomial coefficients." I do not believe it runs counter to Mhym's intention to remove "examples within examples" because the purpose of the illustrative example is to render the article more accessible to our non-technical readership. To my mind, it also conveys a richer, more intuitive feel for what's really going on in binomial proof than can be conveyed by the more formal, algebraic explanation on its own.—PaulTanenbaum (talk) 14:20, 7 November 2018 (UTC)